CZ318395A3 - Engine or pumping mechanism with pistons provided with pressure rollers for bearing against plate cam - Google Patents

Abstract

In a hydraulic pump or motor comprising a cylinder block (8) rotatable relative to a cam surface (3), pistons (11) slidable in cylinder bores (10) in the block and thrust rollers (23) carried by the pistons for cooperation with the cam, means are provided for preventing each piston from rotating about the axis of its cylinder. The rotation preventing means comprises a pair of sector shaped wedging parts, each part being disposed in a recess formed between the end of the roller and the inside face (10) of the cylinder bore. One of the wedging parts includes a groove (36) extending parallel to the axis of the cylinder and into which projects one branch of a U-shaped member fixed to the cylinder block (8). A hole (30) formed in the periphery of the block receives the other branch thereby to fix the U-shaped member in position. Several distinct ways of retaining said other branch of the U-shaped member in the hole (30) are described. <IMAGE>

Description

.Ictor or purse piston, Tuesday has pistons with pressure rollers supported on the cam disc

ColcSt techniques

Vv-e = 5 pertains to the hydraulic rotor rotary with pistons provided with a thrust; and the roller disc.

sbo pumping mecha · čkv replacing on

BACKGROUND OF THE INVENTION

French patent application 2,551,535 discloses and shows a hydraulic motor or pump mechanism comprising: a cam disk; a cylinder block mounted rotatably relative to the cam disc about a rotation axis; at least one cylinder formed in the cylinder block; at least as many pistons as there are cylinders, each piston mounted slidably within the cylinder along the sliding axis of the clean; as many cam follower piston rods as there is a piston, each pulley being defined in the axial direction by two transverse end faces and mounted on the piston via a rotary bearing to rotate about a pulley axis perpendicular to the sliding axis of said piston; suitable for at least partially penetrating a cylinder in which the piston is slidably supported, while the end of the piston in which the rotary bearing of the rotor is mounted comprises two recesses, each corresponding to at least one free space disposed between the roller surface of the roller, the cylindrical surface and one from the transverse faces of the pulley, the free space being open to the play portion of the piston at least in an area where the cylindrical surface of the pulley is positioned so as to extend above the piston; and two pressure portions for each pulley, each portion located in one of said recesses between a corresponding pulley face and the inner face of the cylinder on which said pressure portion abuts to hold the kiadx in a position parallel to its axis of rotation, wherein in particular, at least one of the two trim parts lies on the piston axis up to the bottom of the recess, so that in the direction of the piston exit from the cylinder, it coaxes with said piston, and secondly said pressing part comprises a groove which is parallel to the piston axis; a protrusion which is fixed relative to the cylinder for rotation about the axis of the piston and which is positioned so as to project relative to said cylinder and is inserted into said groove so as to open the dc face of said pressing part opposite to the corresponding end face of the pulley to keep that the pressure part free to move in the relative clearance or cylinder transmission parallel to the piston axis.

According to the prior art, firstly, the projection is secured relative to the cylinder block by being fixed by or along the transverse end face of the cylinder block, and secondly, in some embodiments, the projection extends through the cylinder block wall between said transverse end face and the interior. cdpcvídaMící rollers.

It should be noted that this technique is plagued by certain disadvantages. In particular, the transverse end face of the cylinder block is not always readily accessible, especially for the middle rows of engines in engines that have my three or more parallel rows of cylinders. Proveoení knows my body, wherein the projection passes through the wall of the block vale u, du ^_ 'e Dála ctvorv crovedené in its own does not improve the válc'oh possibly can;

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SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION The present invention seeks to overcome the aforementioned drawbacks, and to this end has provided a suitable solution with the above described mechanism. It is mounted on the cylinder head so that said first arm is in the hole 3 of said first arm is fixed to the block;

said second arm being inserted into a groove contained in said thrust portion and representing said projection and said U-shaped belt being disposed around said periphery of said cylinder block.

In addition, it is preferable to adopt the following advantageous arrangement: the first U-shaped arm has a transverse diameter which is greater than the direction of said hole in the cylinder block prior to insertion into the cylinder block bore.

in a determined transverse direction, said fastening means constitutes a grip that exists between the first leg and the wall of the hole upon insertion of said first leg into the hole, bringing said determined transverse dimension of the first U-shaped arm substantially in line with said determined transverse direction of the hole.

In a first embodiment, the first U-shaped arm is in the form of an open ring and is made of a resilient material, wherein the day of the transverse dimensions of the ring represents the stated transverse dimension before insertion into the cylinder block hole. The ring is preferably made of metal.

L1 of the second embodiment The first U-shaped arm is provided with teeth whose ends coincide with said determined transverse dimension and have the function of securing said first arm in the wall of said hole. 3, the first arm is shaped as a planar strip defined by two opposing edges, each having said teeth.

Finally, the first U-shaped arm of the third embodiment comprises a Core and a Core Cover Body which is made of a material having a small modulus of elasticity, the modulus of said material preferably not being greater than 10,000 (TiPa).

First, said hole is preferably cylindrical and has an axis which is substantially radial to the rotation axis of the cylinder block and a fixed diameter, and secondly said body is also substantially cylindrical and has a diameter which is u into a hole greater than the specified hole diameter; also said core is formed as a planar strip defined by two opposing edges, wherein each edge is provided with a knurling to secure the core cover body.

In general and also in the first and second embodiments, said bore is cylindrical, its axis being substantially radial to the axis of rotation of the cylinder block, and this axis of the cylinder bore preferably lies in a radial plane containing the axis of rotation of the cylinder block and sliding axis of the piston.

Main advantage of the invention It is firstly possible to achieve piston immobilization relative to the rotation about the cylinder axis in a simple manner, even 1 for the middle rows of cylinders, and secondly to achieve such immobilization without passing through the cylinder wall.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood, and its other characteristics and advantages will be more readily apparent when reading the following description of exemplary embodiments.

This description and drawings are naturally given only as a non-limiting indication. Reference is made to the accompanying drawings in which:

Figure 1 - axial section of a hydraulic motor according to the invention; Figure 2 is a sectional view of a plane comprising the axis of rotation and the axis of one of the cylinders in the engine of Figure 1; figure 3 - a view in section III-III of figure 2;

Figure 4 - a section analogous to that of Figure 2 showing a second embodiment of the engine according to the invention; Figure 5 - a section along line V-V of Figure 4;

Figure 5 is a sectional view analogous to that of Figure 2 showing a third embodiment of the engine according to the invention, and Figure 7 - a section along line VII-VII of Figure 6.

DETAILED DESCRIPTION OF THE INVENTION

The engine of Figure 1 consists of:

- a two-piece housing 1a, 1b held together by screws 2;

- a corrugated cam disc 3 secured to the housing 1 a _t 1b;

an output shaft 6 mounted rotatably relative to the housing about the axis 5 by means of roller bearings 6, the inner end of which is provided with a groove 7;

a cylinder block 8 having a central bore provided with a spline S flush with the spline 7 on the shaft to force the shaft 4 to rotate with the cylinder block 8 and to center the cylinder block relative to the shaft;

- a plurality of cylinders 1 □ arranged radially to the star relative to the axis 5, each comprising a piston 11 which is slidably mounted therein;

a planar face 12, which is formed on the cylinder block 8, and is perpendicular to the axis of rotation 5, with the outlets 13 which are connected to the different cylinders 10; and

- a distributor 14 for distributing liquids to the various cylinders 10. This distributor is provided with a planar face 15 perpendicular to the axis of rotation 5 and located with its face side so as to abut against the cylinder block face 12 and comprises two circular grooves 16 and 17 respectively. and optionally communicating with a fluid source under pressure 18 and a fluid reservoir having no pressure 15 while the device 20. which has a foot and a bracket, forces the liquid distributor 14 to rotate with the part 1 and the housing and channels 21. 22, they connect the grooves 16 and 17 respectively to the planar face 15 and are suitable for successive contact with the cylinder block channels 13 during relative rotation between the cylinder block 8 and the distributor 14.

In a bearing 24 arranged at the end of each piston 11, a roller roller 23 is supported and rotatably mounted about a roller axis 25 perpendicular to the piston axis 25, which coincides with the cylinder axis 1 □. the roller 23 is suitable for at least partially penetrating the cylinder, so that each transverse face 27 defining the roller is adjacent a shoulder 28 which

It is formed in part of the piston 11. that supports the pulley and so in

it allows to create gaps on each side of said roller. Each shoulder corresponds to at least one gap, which lies at least between the surface of the cylinder 1 □. the cylindrical surface of the pulley 23 and the corresponding transverse surface 27 of the pulley, said gap also being open at the top of the piston at least in the regions where the pulley is positioned so as to extend above the piston.

The above-described arrangements can be found in each of the illustrated embodiments. L! of the illustrated embodiment, the plane perpendicular to the axis 25 of the pulley 23 and including the piston axis 26 is the symmetry plane for the piston 11, the bearing 24, the pulley 23 and the two gaps. In the context of the invention, it is also possible to have an arrangement which is asymmetric and in which the gaps are not symmetrical relative to each other about a plane perpendicular to the pulley axis 25.

In each embodiment, provision should be made for means to keep the pulley 23 supported on the piston 11 axially in position within its bearing and to ensure its angular orientation relative to the piston axis 26 to be constant to ensure that the pulley 23 is positioned facing the cam and will be properly oriented with respect to the cam disk so that it is able to roll on the cam disk. The means that are designed to achieve this goal vary between embodiments and are described below.

In the embodiments of Figures 2 to 7, each gap defined between the shoulder 26 of the piston 11 and the inner wall of the cylinder 1 obsahuje comprises a pressing portion 25 of corresponding shape having a cross-section that is substantially crescent-shaped, see Figure 3. has a planar face 25A oriented to one end face 27 of the roller 23 and a cylindrical face 25B in

abutting the inner face of the cylinder 1 □ and thus provides axial wedging of the pulley in a direction causing the pulley face 27 to rest against the face 25A of the portion 25.

In the embodiment of Figures 2 and 3, one of the pressing portions 29 has a groove 36 which is arranged parallel to the piston axis 26 and also of the cylinder and is open to the top face of the pressing port 29. A blind cylindrical bore 30 is formed in the cylinder block. which has a radial axis 31 arranged in a plane that includes both the piston axis 26 and 1 rotation axis 5 and is open to the peripheral face 32 of the cylinder block B which is cylindrical about the axis 55. The clamp, which in the present example is made of metal is designed and generally U-shaped with two arms. The first L-shaped arm 33 has a substantially cylindrical open ring 34 at one end, the outer diameter of which is slightly larger than the diameter of said hole before being inserted into the hole 30.

30. The ring 34 is embedded in a hole 30 in which it remains retained by the elastic deformation of said ring, which is preferably made of steel. The second U-shaped arm 35 is held in the cylinder 10 and in the groove 36 of the pressure portion 29 and allows said pressure portion 29 to slide parallel to the piston axis 26. Finally, the U-shaped belt 37 overlaps the peripheral face 32 of the cylinder block. It should be noted that the hole 30 is adjacent to the opening 36 of the cylinder 10 and is separated from it only by a thin wall 39.

In the embodiment according to Figures 4 and 5, only the shape and construction of the clamp are altered with respect to the embodiment according to Figures 2 and 3. Clamp It is still a LJ-shaped metal profile made of steel and taken from a strip of steel with a cross-section in the form of a trough. The first U-shaped leg 133 is flat and defined by two substantially parallel opposing edges 40 which are provided with teeth 41 suitable for engaging the walls of the hole 30 after being inserted therein. The distance between the points belonging to the different edges 240 ored by inserting the first arm 133 into the hole 30 is greater than the diameter of said hole. The insertion is achieved by pushing the frame onto the hole. Since the embodiment of Figures 2 and 3 is such that the second leg 135 of the LJ profile is located within the cylinder 10 and is held in the groove 36 of the pressing portion 29, this allows it to slide parallel to the axis 26 of the piston. The U-profile belt 37 is finally positioned above the circumferential face 32 of the cylinder block B.

In the embodiment of Figures 6 and 7, only the shape and construction of the first clamp arm differs from the embodiment of Figures 2 and 3. The clamp is U-shaped and has a metal core made of steel. The core 233 of the first U-shaped leg is defined by two substantially parallel edges provided with indentations 42 which are spaced apart from one another in a width that is less than the diameter of the hole 30. This core portion is threaded in a cylindrical stud 43 made of modulus of elasticity It is small, for example, of a plastic material having a modulus of elasticity not greater than 10,000 fYlPa. Prior to insertion into the hole 30, the diameter of the bolt 43 is slightly larger than the diameter of the hole 30. The second leg 235 of the U-profile is located within the cylinder 10 and is held in the groove 36 by the pressing portion 25 thereby allowing it to slide parallel to the piston axis 26. The U-profile belt 237 lies at the end on the peripheral face 32 of the cylinder block 6.

In all three embodiments described, the first arm 33; 133; 233-43 of the U-profile defined transverse dimension, i.e. the diameter of the ring 34 in free state, the gap between the opposing teeth 41 or the diameter of the bolt 43, this dimension being greater than the diameter of the hole 30 and more generally greater than the transverse dimension of the hole. a transverse direction, i.e. more generally in the case where the hole 30 does not necessarily have to be a circular cylinder. The first arm is always fixed in the hole 30 such that it is adapted by force due to said determined transverse dimension of the first arm 33; 133; 233-43 of the U-profile, which substantially aligns with the determined transverse direction of the hole 30.

The ring 34, which is made of steel, is in this case a little resilient to allow insertion into the hole 30 and then being held in place within the hole.

In each of the presented embodiments, the clamp is held relative to the cylinder block 6 and consequently 1 relative to the cylinder

10, and is thus suitable for holding the piston 11 and the pulley 23 in a predetermined orientation relative to the piston axis 26, thus allowing the pulley 23 to be held in a satisfactory position within the cam disc J.

Note that the hole 30 may be formed anywhere in the peripheral face 32 of the cylinder block 6, and in particular at locations spaced from the end transverse faces BA of said cylinder block, which may be particularly close to the cylinders in some inner row. engine cylinder having three or more parallel rows of cylinders. Moreover, since the hole 30 has a radial direction, i.e. the axis 31 extends substantially through the axis of rotation j. The clamp is retained without forming a through hole in the wall of the cylinder 22 so that the cylinder is not damaged. It should also be noted that it is easy to produce radial holes in the manufacture of a cylinder block having radially opposed cylinders.

The invention is not limited to the described embodiments, but on the contrary reaches every variant that can be prepared outside them without departing from the scope or spirit of the invention.

Mí- κ

Claims (9)

1. A hydraulic motor or pump mechanism comprising: - a cam disc (3); - a cylinder block (8) mounted rotatably relative to the cam disk about a rotation axis (5); in - at least one cylinder (10) formed in the cylinder block; - at least as many pistons (11) as there are cylinders (10), each piston being slidably mounted in the cylinder (10) along the sliding axis (26) of the piston; - as many cam rollers (23) for rolling on the cam disk as there are pistons, each roll (23) It is limited in axial direction by two transverse end faces (27) and for rotation about the axis (25) of the pulley perpendicular to the sliding axis (26) of said piston. It is supported on the piston (11) via a rotary bearing and is suitable for at least partial penetration. into a cylinder (10) in which the piston is slidably mounted, while the end of the piston in which the rotary bearing for the rotor is mounted includes two shoulder (28), each of which corresponds to at least one gap that lies within the at least between the roller surface of the roller, the roller surface (10) and one of the transverse faces (27) of the roller (23), said gap being open to the top of the piston (11) at least in an area where the roller surface is arranged such that it protrudes above the piston; and - two thrust portions (25) for each roller (23), each of said portions being arranged in one of said two shoulders between a corresponding roller face (27) and an inner face of the cylinder (10) by which said thrust portion supports to hold the roller in a position axially parallel to its axis of rotation (25), while firstly at least one of the two thrust portions (29) extends on the axis of the piston up to the bottom of the shoulder such that ....... in the piston leaving the cylinder It is displaced with said piston, and secondly said pressing part (29) comprises a groove (36) which runs parallel to the piston axis (26) and which is open to the face said thrust portion facing away from the corresponding end face (27) of the pulley, wherein a projection (35, 135, 235) is mounted relative to the cylinder relative to the cylinder for rotation about the piston axis and is configured to protrude relative to said cylinder; It is inserted into said groove (36) so as to leave said thrust portion free to move relative to the cylinder parallel to the piston axis (26), said mechanism characterized in that the hole (20) formed in the cylinder block (6) opens into its a peripheral face (32), while a generally U-shaped portion having a first arm (33); 133; 233-43) and the second arm (35); 135; 235), which are interconnected by a band (37); 137; It is mounted on the cylinder block by supporting said first arm (33); 133; 233-430) into said hole and fastening said first arm with respect to the cylinder block by fastening means while said second arm (35); 135; 235 / It is inserted into a groove contained in said pressing part (29) and represents said projection, and said belt (37); 137; It is located above said cylinder block circuit (32). Mechanism according to claim 1, characterized in that the first leg of the profile (U) has a predetermined dimension which is greater than the direction of said hole (30) in a specified transverse direction prior to introduction into the cylinder block bore, said fixing means being a clamp that exists between the first leg and the wall of the hole after introduction of said first arm of the dc hole, which brings said determined transverse diameter of the first leg of the profile (U) substantially coincident with the specified transverse direction of the hole. (Mechanism according to claim 2, characterized in that the first leg of the profile (U) has the shape of an open ring (34) and is made of a resilient material, wherein one of the transverse dimensions of said ring represents the specified transverse dimension. 4. (Mechanism according to claim 3, characterized in that said ring is made of metal. (Mechanism according to claim 2, characterized in that the first leg (U) (133) is provided with teeth (41) whose ends coincide with said determined transverse dimension and have the function of securing said first leg in the wall of said holes (30). 8. (Mechanism according to claim 5, characterized in that the first arm is shaped as a planar strip defined by two opposing edges (40) each having teeth (41). (Mechanism according to claim 2, characterized in that the first leg of the profile (4) comprises a core (233) and a core cover body made of a material having a small modulus of elasticity. (Mechanism according to claim 7, characterized in that the modulus of elasticity of said material is not more than 10,000 (MPa). (Mechanism according to claim 7 or 6, characterized in that said Cores (233) are formed as a planar strip defined by two opposite edges, wherein each edge is provided with a notch (42) to secure the core cover body (43). A mechanism according to any one of claims 7 to 9, characterized in that said hole (30) is cylindrical and has an axis (31) that is substantially radial with respect to the axis (5) of the cylinder block (6). and said diameter and second, said body (43) is also substantially cylindrical and has a diameter which is greater than the determined diameter of the hole before introduction of the first profile leg (U) into the hole (30). A mechanism according to any one of claims 1 to 5, wherein said hole is cylindrical and its axis (31) is substantially radial with respect to the axis (5) of rotation of the cylinder block. A mechanism according to claim 10 or 11, characterized in that the axis (31) of the cylindrical bore (30) lies in a radial plane which comprises the ace of rotation of the cylinder block (6) and the sliding axis (26) of the piston (11).